The many modes of gene regulation

Putting the puzzle pieces together

The third session, “Transcriptional Regulation During Growth and Development,” is devoted to how gene regulatory mechanisms are played out in vivo. Joaquin Espinosa (University of Colorado at Boulder) will describe his work on transcription regulation by the p53 network. Activation of p53 can lead to distinct outcomes depending on the signal and cell context, suggesting that cells employ different transcription co-regulators to tailor the p53 response to oncogenic stimuli.

Susan Mango (Harvard University) will describe the role of the FoxA family of transcription factors in establishing the foregut during development. Mango’s findings illuminate how these factors provide the foundation for the transcription pathways that govern organ development in the C. elegans foregut.

Cell differentiation involves an integration of information provided by transcription-factor activity and chromatin structure. Ken Zaret (The University of Pennsylvania) will discuss the role of pioneer transcription factors in mammalian cell differentiation, describing how they uncover specific segments of the genome to make them accessible and amenable for activation.

Nucleosomes vs. the transcription machinery

The final session, “Interplay Between Chromatin Structure and the Transcription Machinery,” will expand on the idea that the transcription machinery can serve as a barrier to chromatin formation. Karen Adelman (National Institute of Environmental Health Sciences) will describe how the pausing of Pol II during early elongation prevents nucleosome assembly near promoters, thereby enhancing gene expression and poising genes for robust activation.

Gordon Hager (National Cancer Institute) will discuss recent findings that signal-dependent binding of nuclear receptors to DNA often targets sites of pre-opened chromatin. This suggests that the pre-existing chromatin structure in a given cell type or condition can affect the activity of nuclear receptors significantly.

Transcription factors themselves also can be targets of post-translational modifications. Or Gozani (Stanford University) will describe how lysine methylation of both histones and transcription factors is regulated to affect gene expression.

Karen Adelman (adelmank@niehs.nih.gov) is a principal investigator at the National Institute of Environmental Health Sciences, and Yang Shi (yang_shi@hms.harvard.edu) is a professor at Harvard Medical School and Children’s Hospital Boston.